From among these articles one of the most used is the classic plastic bag, in various formats; also very widely used are paper, carton or synthetic bags, designed to contain articles of clothing, shoes or other objects packed in relative boxes.
All of these articles exhibit handles, variously conformed, which are designed to enable a user to transport the load easily by suspension instead of having to hold the article directly using one or both hands placed underneath.
The bags referred-to above are very liable to customization and therefore become effective publicity vehicles, such that supply of them, often free of charge, represents not only an act of courtesy towards the customer but also a form of promotion for the store or marks of products sold by the store.
Loose or packed products can be inserted in the bags; excluded from the products that can be placed therein are articles having considerable horizontal dimensions and which require being held in a horizontal orientation.
A first example of this is the cardboard box supplied for take-away pizzas, which in order to be transported, whether single or stacked, have to be held from below, not without some discomfort due to the heat emanated to the carton from the contents and with the risk that an awkward action or unexpected contact with obstacles might cause the carton to be dropped.
A further example relates to large-format trays used for pastry or fresh pasta asciutta products, which are packed carefully such as not to crush the contents and which must thereafter be handled with care by the customer in order to prevent damage thereto.
To the difficulty of transporting objects by holding them from below can be added other objective difficulties, in particular when the equilibrium provided by a single hand is precarious and other actions have to be performed, such as taking out keys, opening doors or other like maneuvers.